SpaceX propulsion head and founding employee Tom Mueller spent about an hour on Skype with members of NYU’s Astronomy Club earlier this month. Perhaps it was because he was talking to eager students (and not investors or colleagues), but his comments came across as genuine and even–especially in regards to SpaceX’s competition–blunt.
Broadly, Mueller did not hold back about the way other rocket companies do business. Reflecting on the process of developing SpaceX’s signature Merlin engine, Mueller recounted the frustration of trying to work with slow, expensive parts suppliers before the company decided to create most of its own components from scratch. He said now “we avoid space vendors like the plague.”
Mueller also laughed (literally, laughed) at the deeply ingrained conservatism common to most existing rocket producers. When SpaceX started, Mueller said, “we were ridiculed by the other big companies in the launch vehicle business.” But as it became clear that SpaceX really could build a reusable rocket that would dramatically lower launch costs, they began to “try to destroy [SpaceX] politically, and use other means [to compete].”
Now, those competitors have come around to the idea of reusable rockets, but Mueller doesn’t think much of some of their efforts:
The Russians are saying they’re coming up with a rocket that can beat SpaceX, which is entertaining . . . because they’ve been working on their Angara rocket for 22 years, and launched it once. And suddenly they’re going to be coming up with a low-cost one.
Mueller suggested most competitors will only have a harder time keeping up in coming years, arguing that SpaceX’s “Mars rocket” (probably a reference to the nascent Interplanetary Transportation System) “is going to be the real game-changer . . . we want like a hundred or more reduction in costs . . . So once we’re flying that, all other rockets will probably be obsolete.”
Get Data Sheet, Fortune’s technology newsletter.
Mueller also provided some exciting insights into SpaceX’s future plans. A “Block 5” version of the Falcon 9 rocket, which will debut later this year, will have a 24-hour turnaround time thanks to reusable thermal protection. SpaceX’s “next vehicle”—implicitly, the Falcon Heavy—will be the first to use methane-based fuel, which can be produced on Mars. And Mueller confirmed SpaceX’s plan to launch a huge network of satellites to provide global wireless internet, which he said would “eventually double the bandwidth of the internet that exists” and particularly improve service in remote areas.
Perhaps Mueller’s least guarded comments were about his boss, Elon Musk. “It’s quite a trip, working for Elon,” Mueller said. “It’s different every day, because it all depends on what mood he’s in. He’s been in a great mood lately; we’ve been very successful, and Tesla’s been doing quite well, [but] he’s still extremely demanding.”
While Musk almost always presents an upbeat, even goofy public image, Mueller confirmed that the SpaceX and Tesla CEO can be both hard-driving and mercurial. Mueller elaborated:
We’ll have, you know, a group of people sitting in a room, making a key decision. And everybody in that room will say, basically, ‘We need to turn left,’ and Elon will say ‘No, we’re gonna turn right.’ And that’s how he thinks. He’s like, ‘You guys are taking the easy way out; we need to take the hard way.’
All of that’s just scratching the surface of Mueller’s comments, which also encompassed Tesla’s manufacturing philosophy, nuclear rocket propulsion, and life on Mars. A full transcript of the talk, courtesy of SpaceX fans on Reddit, can be found here.
